I don't think it's a con (asking you to attach a credit card to your Google account). I think it's a way for Google to collect a developer's fee for using Google Maps. The gist I got from this whole API Key thing was that Google realized that they were missing out on collecting even more revenue from all the various software developers who were designing their software around Google's product. So, they decided that anyone who uses it a lot, like Tyre, is now going to have to consider themselves as developers the way Google defines them, and they're making them pay a fee to obtain the API key so they can continue using Google's maps. That was one reason that the original Tyre program stopped working with Google Maps; because they wouldn't pay for the API Key. For individual users, I think the Google account and credit card is a way for Google to permit individual use of the maps without being a developer, but it leaves them a back door to track the amount that you use the maps. They can no doubt keep track of your usage through Tyre via your Google account, and I suppose if you reach a certain threshold of map usage, they begin charging you a fee. I have no idea what that threshold would be, or even if my theory is correct, but it would make sense if Tyre now requires a Google account in order to use it.
I miss Tyre a lot; it was the best mapping program I'd found for guys who ride motorcycles (probably because it was written by a couple guys who ride motorcycles). And with Google's current stance, I doubt you'll see another Windows-based freeware mapping program created by independent developers that takes into account the needs of motorcyclists.
I've gotten myself to the point where I can use Basecamp enough to create a route, and Basecamp does have the advantage of not needing an internet connection to work. I just wish Garmin's software developers would take a hint from Tyre and introduce a little simplicity into Basecamp.
Between Google and Amazon, there soon isn't gonna be any money for anyone else to use; they're going to have it all.
"No matter where you go, there you are."